This invention relates to an apparatus for treating waste liquor produced concomitantly with development processing of light-sensitive photographic materials using an automatic processing machine for photography (hereinafter abridged as "photographic process waste liquor" or "waste liquor") through concentration by evaporation, and, more particularly, to an apparatus for treating photographic process waste liquor through concentration by evaporation, that is suited for treating the waste liquor by installing the apparatus inside the automatic processing machine or in the vicinity thereof.
In general, the photographic processing of light-sensitive silver halide photographic materials is carried out by combining steps employing processing solutions having one or more of the functions such as developing fixing, washing, etc. in the case of black and white light-sensitive photographic materials, or color developing, bleach-fixing (or bleaching and fixing), washing, stabilizing, etc. in the case of light-sensitive color photographic materials.
Then, in the photographic processing to process a large quantity of light-sensitive materials, there is employed a means in which the performance of processing solutions is constantly maintained by removing, while replenishing components consumed by the processing, components that may be thickened or concentrated during the processing by dissolving-out in the processing solution or by evaporation (for example, bromide ions in the developing solution, silver complex salts in the fixing solution, etc.). A replenishing solution is supplied to the fixing solution for the purpose of the above replenishing, and a part of the processing solution is thrown away for the purpose of removing the above thickened or concentrated components in the photographic processing.
Recent years, because of environmental pollution or for economical reasons, replenishing solutions for photographic development processing solutions as well as washing water which is a replenishing solution for washing are undergoing a change such that they are used in a system in which the quantity of the replenishment has been greatly decreased. The photographic process waste liquor, however, is led from a processing tank of the automatic processing machine through a waste liquor pipe and thrown away in sewerages or the like after diluted with waste liquor of washing water or cooling water for the automatic processing machine.
However, because of tightened regulation in recent years against the environmental pollution, although it is possible to throw away washing water or cooling water in sewerages or rivers, it has been made substantially impossible to throw away the photographic processing solutions other than these [for example, developing solutions, fixing solutions, color-developing solutions, bleach-fixing solutions (or bleaching solutions or fixing solutions), stabilizing solutions, etc.]. For this reason, every photographic processing dealer has the waste liquor collected by dealers speciallized in the waste liquor treatment or installs an equipment for pollution-preventive treatment. However, the way of placing the waste liquor treatment to dealers' care may necessarily require a considerable space for keeping the waste liquor stored and may also be very expensive from the viewpoint of cost. Also, the equipment for pollution-preventive treatment may involve disadvantages such that it requires very large initial investment (or initial cost) and a considerably vast place for the equipment.
Moreover, although known methods for pollution-preventive treatment to decrease the burden to environmental pollution by photographic process waste liquor include an activated sludge method (Japanese Patent Publication Nos. 12943/1976, 7952/1976, etc.), an evaporation method (Japanese Unexamined Patent Publication No. 89437/1974, Japanese Patent Publication No. 33996/1981, etc.), an electrolytic oxidation method (Japanese Unexamined Patent Publication Nos. 84462/1973 and 119458/1974, Japanese Patent Publication No. 43478/1978, Japanese Unexamined Patent Publication No. 119457/1974, etc.), an ion-exchange method (Japanese Patent Publication No. 37704/1976, Japanese Unexamined Patent Publication No. 383/1978, Japanese Patent Publication No. 43271/1978, etc.), a reverse osmosis method (Japanese Unexamined Patent Publication No. 22463/1975, etc.), a chemical treatment method (Japanese Unexamined Patent Publication No. 64257/1974, Japanese Patent Publication Nos. 37396/1982, Japanese Unexamined Patent Publication Nos. 12152/1978, 58833/1974 and 63763/1978, Japanese Patent Publication No. 37395/1982, etc.), etc. these can not be said to be sufficient.
On the other hand, taking account of restriction from the viewpoint of water resource, increase in cost for water supply and drainage, simplicity in equipment for automatic processing machines, work environment surrounding the automatic processing machines, there is a recent increasing spread of photographic processing that employs an automatic processing machine requiring no piping outside the automatic processing machine, for feeding and discharging the water for washing (i.e., the so-called non-washing automatic processing machine). In such processing, it is desired to dispense with also the cooling water for controlling the temperature of processing solutions. Such photographic processing that uses substantially no washing water or cooling water has a feature that, because of no dilution with water, its burden to environmental pollution is very large and on the other hand the quantity of waste liquor is small as compared with the instance in which the photographic process waste liquor is brought from the automatic processing machine.
Accordingly, because of the smallness in the quantity of waste liquor, the exterior piping for feeding and discharging solutions can be omitted, so that there can be eliminated the disadvantages such that, because of the equipment of the piping that can be regarded as a defect of the conventional automatic processing machines, the machine can be moved only with difficulty after it has been installed, provides a narrow space for footing, requires a great expense for pipework at the time of the installment, and requires an energy cost for hot-water feeding pressure. Thus, very great advantages can be exhibited such that the machine can be made so compact and so simple that it may be used as an office machine.
On the contrary, however, such waste liquor has a very high burden to environmental pollution, and thus it has become quite impossible to throw away it even into sewerage, not speak of rivers, in the light of the regulation of environmental pollution. Moreover, although the waste liquor quantity can be said to be small in such photographic processing (i.e., the processing in which no washing is carried out by use of a large quantity of running water), the waste liquor may amount to about 10 lit. per day, for example, even in color photofinishing laboratories of relatively small scale.
Accordingly, in general, the waste liquor is collected by waste liquor collecting dealers, and made harmless after secondary and tertiary treatments. However, because of an increase in the cost for the collection, not only the fees for taking over the waste liquor is increasing year by year, but also the dealers are not willing to come to collect the waste liquor to miniature photofinishing laboratories because of its low collection efficiency, thus causing problems such that shops are full of waste liquor.
On the other hand, for the purpose of solving these problems and with an aim at making it possible to readily carry out the treatment of the photographic process waste liquor also in the miniature photofinishing laboratories, it is studied to heat the photographic process waste liquor to carry out evaporation of water to dryness or effect solidification as disclosed, for example, in Japanese Utility Model Unexamined Publication No. 70841/1985. As known in the studies by the inventors, harmful or very ill-smelling gases such as sulfite gas, hydrogen sulfide and ammonia gas may generate when the photographic process waste liquor is subjected to the evaporation treatment. These were found to be generated because ammonium thiosulfate and sulfites (ammonium salt, sodium salt or potassium salt) frequently used as the fixing solution or bleach-fixing solution of the photographic processing solutions are decomposed owing to high temperature. Moreover, at the time of the evaporation treatment, the water or the like contained in the photographic process waste liquor is vaporized in the form of vapor to increase the volume and increase the pressure in a evaporating vessel. Therefore, because of this pressure, the above harmful or ill-smelling gases may necessarily leak outside the evaporation treatment apparatus to cause great difficulties from the viewpoint of the work environment.
Now, to solve these problems, Japanese Utility Model Unexamined Publication No. 70841/1985 disclosed a method in which an exhaust gas treating section comprising activated carbon or the like is provided at an exhaust pipe section of the evaporation treatment apparatus. This method, however, has a serious disadvantage that the vapor from a large quantity of water contained in the photographic process waste liquor causes sweating or moisture condensation at the exhaust gas treating section, so that a gas absorption treatment agent is covered with the water to instantaneously lose its gas absorption ability. Thus, this method has not been put into practical use.
To solve these problems, the present applicants have previously proposed, in carrying out the evaporation treatment of photographic process waste liquor, a method of, and an apparatus for, treating photographic process waste liquor, provided with a cooling and condensing means capable of condensing the vapor generated by the evaporation and further treating the condensate water generated by condensation, simultaneously also treating uncondensed components, to discharge them to the outside.
However, there were found the following problems in the above proposal. Specifically, the vapor generated by evaporation treatment, which is condensed by a cooling and condensing means, may be discharged outside the apparatus in a higher proportion without being condensed if the cooling and condensing efficiency is low. Even if it is treated by activated carbon, ill-smelling harmful gas may be discharged outside the apparatus also in a higher proportion. Further, there are instances where the condensate water produced by condensation by the cooling and condensing means smells when thrown away, or has so a high burden to environmental pollution that it can not be discharged into sewerages or the like as it is. Still further, when the waste liquor is treated by evaporation, the waste liquor in an evaporation vessel may spout by bumping from a lead-in pipe for leading the vapor to the cooling and condensing means, and flow into a stock tank (or reservoir) of condensate water. If it is attempted to prevent an accident due to such pumping, it becomes necessary to make very large the volume at the air space of the evaporation vessel. Still further, because of the space very limited in the miniature photofinishing laboratories, not only the ill smell generated by the treatment of the photographic processing solutions is questioned, but also the space for installing the photographic process waste liquor treatment apparatus itself is questioned. The cost for the apparatus and the running cost also involve important problems. Accordingly, a compact, inexpensive and running-cost-low treatment apparatus that can treat the photographic process waste liquor without generating ill-smelling harmful gas has been sought after.